AD/CON/56 Amdt 1 - Number Two Crankcase Main Bearing Integrity

Overview

The Civil Aviation Safety Authority (CASA) has issued Airworthiness Directive AD/CON/56Amdt 1, effective as of 1990, to address issues related to the main bearing integrity of Teledyne Continental Motors piston engines, specifically the TSIO 520BE engines with serial numbers between 528001 and 528337 installed on Piper PA46-310P Malibu aircraft. This directive was introduced to mitigate risks associated with the loss of torque in the thru-bolt of the engine's crankcase, which can lead to fretting of the crankcase mating flanges and subsequent migration of the number two main bearing. The directive mandates specific inspections and maintenance actions to ensure the continued airworthiness of affected aircraft, reflecting CASA's commitment to maintaining stringent safety standards in civil aviation. The directive outlines compliance requirements, including inspections and checks to be conducted at specified intervals or before further flight, depending on the stage of the aircraft's service history.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, outlines the Airworthiness Directives that govern the maintenance and safety of aircraft within Australian airspace. This legislation applies to specific Teledyne Continental Motors Piston Engines, particularly the TSIO 520BE engines with serial numbers ranging from 528001 to 528337 as installed in Piper PA46-310P Malibu aircraft. The regulation necessitates detailed inspections and checks on these engines to ensure their continued airworthiness. The requirements include inspecting the crankcase for end play, carrying out a thru-bolt torque check, and inspecting the number two crankcase main bearing, with specific guidance provided through referenced Technical Service Instructions. The directive mandates that these inspections occur at specified intervals, either before further flight or within set time limits after certain events. The Civil Aviation Safety Authority has the jurisdiction to enforce these directives, which apply nationally, ensuring consistent safety standards across all Commonwealth territories. The Civil Aviation Regulations 1998 also allow for the creation of subordinate instruments to extend or restrict the application of the legislation. These subordinate instruments may provide further clarifications or additional requirements to ensure compliance with the overarching objective of maintaining air safety. However, the primary directive focuses on the specified engines and aircraft, with no broader exemptions or exclusions mentioned within the provided text. The directive’s applicability is clearly defined, ensuring that all relevant parties are aware of their obligations under the law.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39 - 106, contains specific provisions governing the airworthiness of Teledyne Continental Motors piston engines, particularly focusing on the crankcase main bearing integrity of TSIO 520BE engines serial numbers 528001 through 528337 fitted to Piper PA46-310P Malibu aircraft. The main operative sections of the legislation (AD/CON/56Amdt 1 Number Two Crankcase Main Bearing Integrity) detail the mandatory inspections and actions required to ensure the safety and airworthiness of these engines. Specifically, Section 1 mandates an inspection of the crankcase for end play, a through-bolt torque check, and an inspection of the number two crankcase main bearing, as outlined in TCM SB M89-14 Sections A, B, and C respectively. The repetitive nature of these checks may cease once the crankcase assembly is disassembled to inspect the crankcase mating flanges for fretting, and new bearings are installed. These regulations impose several obligations on the parties involved, particularly the operators and maintainers of the affected aircraft. The primary obligation is to ensure that the inspections and checks are conducted prior to further flight and at regular intervals as stipulated in the legislation. For instance, the crankcase end play inspection must be conducted before further flight and then at intervals not exceeding 25 hours of time in service (Section 1). The through-bolt torque check must be performed before further flight, and the number two crankcase main bearing inspection must be carried out prior to further flight and thereafter at intervals not exceeding 200 hours of time in service (Sections 2 and 3). Failure to adhere to these obligations can result in significant safety risks, including potential engine failure, which could endanger the aircraft and its occupants. The legislation also outlines the consequences for non-compliance with the specified requirements. Any breach of these provisions can result in severe penalties. While the specific penalties are not detailed in the text provided, under Australian law, breaches of civil aviation regulations can lead to substantial fines and imprisonment for individuals, as well as fines for corporations. Additionally, the aircraft may be grounded until the necessary inspections and repairs are completed, leading to operational disruptions and potential financial losses for the operators. It is crucial for all parties involved to strictly adhere to these regulations to maintain the highest safety standards in civil aviation.